Monitoring of nitrogen-oxides in busy streets: no - NO2 problem?
Meting van stikstofoxiden in drukke verkeersstraten: no - NO2 problem?
Meulen A van der , Swaan P
RIVM Report 222101010
In heavy loaded traffic situations, large negative NO2 measurement data are regularly encountered. This is directly due to the technical construction of the employed standard Philips PW9762 nitrogen-oxide monitor. Upon presentation of the cumulative frequency distribution, the higher percentile values will be overestimated consequently ; particularly 10 and 15% for the 95 and 98-percentile one respectively. The use of 3-hourly floating averages, instead of the customary hourly ones enables a realistic estimate of these higher NO2- percentiles. Appropriate adaption of the shape of the sample delay volume enables the proper establishment of NO2, even in the afore-mentioned traffic situations.